K1x, an AI-native platform for private markets tax data, has closed a $175m growth investment led by Sumeru Equity Partners, with participation from existing backer Edison Partners.
Sumeru will take a majority stake in the business as part of the transaction. Edison Partners, which has now invested in K1x three times since 2022, also contributed to the round.
The capital injection arrives as private markets continue to attract a broader investor base beyond traditional institutions, creating a surge in the volume and complexity of tax reporting obligations. The industry is estimated to bear an annual burden of $27bn in tax reporting costs. Growth in pass-through structures such as LLCs and S corporations has heightened demand for Schedule K-1 creation and reporting, revealing significant gaps in existing infrastructure.
K1x was founded to address this challenge. The company’s patented platform uses AI to automate the extraction, aggregation and standardisation of complex K-1 data, replacing manual processes with a unified, scalable approach to tax reporting across accounting firms, general partners, limited partners and technology platforms.
The company intends to deploy the proceeds across several areas, including deepening its core platform capabilities, accelerating product development, expanding its application of machine learning and generative AI, and strengthening customer experience and support infrastructure. K1x currently works with 44 of the 100 largest institutional investors and 20 of the top 25 accounting firms, and handles data across K-1s, 1099s, W-2s and 990s.
K1x CEO John LaMancuso said, “Where tax compliance in public markets runs like a Swiss watch, private markets still run on manual processes, unstructured documents and data, and fragmented systems that cannot scale. The complexity of K-1 forms, compounded by the increase in volume, proves that the operational strain is no longer seasonal – it’s structural. We are excited to work with Sumeru on solving this ongoing tax data infrastructure problem.”
Sumeru managing partner Kyle Ryland said, “Private market tax data is one of the last major workflows in financial services still running on manual processes and spreadsheets — K1x is purpose-built to change that. What drew us to K1x is the depth of the competitive advantage: patented AI models trained on uniquely complex tax forms, a connected data layer spanning K-1s, 1099s, W-2s, and 990s, and trusted relationships with 44 of the 100 largest institutional investors and 20 of the top 25 accounting firms. This isn’t a point solution — it’s the infrastructure layer for private market tax compliance. We look forward to partnering with the team to accelerate growth in a market that remains over 90% unserved and increasingly critical as the $20+ trillion alternatives landscape expands, and investment structures grow in complexity.”
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